1. Field of the Invention
The present invention relates generally to weatherstrips, and more particularly to a weatherstrip having an overhanging barrier fin and method of manufacture.
The overhanging barrier fin is an inverted shallow V-shaped member having first and second web portions joined along a common fold line. The barrier fin is arranged with the first web portion extending substantially vertically, and the second web portion overhanging the sealing body of the weatherstrip.
2. Description of the Prior Art
It is well known to provide a weatherstrip having rows of pile extending longitudinally from a flexible backing strip, and having a substantially impervious barrier fin comprising a thin film or sheet of plastic material secured to the strip and/or the pile. The fin supplements the sealing action of the pile by increasing the resistance to the infiltration of foreign material such as air, moisture or the like through the weatherstrip. An example of this weatherstrip construction is shown in U.S. Pat. No. 3,175,256.
It is also known to locate the barrier fin on one side of the body of pile as shown in U.S. Pat. No. 3,404,487, or on both sides of the pile as shown in U.S. Pat. No. 3,266,190.
It is further known to provide a barrier fin in which the free edge of the fin extends beyond the free end portions of the sealing body adjacent thereto. In use, the free edge of the fin is bent over at least a part of the free end portion of the sealing body. This weatherstrip construction is disclosed in U.S. patent application Ser. No. 042,999, now U.S. Pat. No. 4,214,930, by A. J. Burrous and which is assigned to the same assignee of the present invention.
One of the major problems with weatherstripping containing barrier fins is an increase in the break-away force required to open a sliding member such as a door or window. The break-away force is the force required to overcome the inertia of the door or window when starting to open it from a fully closed position. The fin tends to snap over or reverse itself as the sliding door or window is moved from a fully closed position, thereby increasing the resistance to such movement to the point that the break-away force required to open a door or window has become excessive. Hence, small children or elderly persons often cannot open the doors or windows having such weatherstripping.
Another problem with weatherstripping containing conventional barrier fin is some leakage of air and moisture past the fin in those situations where the entire fin does not bend in the same direction for some reason or other. In such situations, normally alternate longitudinally and vertically extending portions of the fin will be bent laterally in one direction while the alternate portions therebetween are bent laterally in the opposite direction. The result is a vertical displacement of the upper edge of the fin from the sliding surface of the door or window forming a clearance or space at the node between each pair of oppositely bent portions through which air and moisture can pass.
Still another problem encountered in the use of conventional weatherstripping containing a conventional barrier fin is improper sealing between the upper edge of the substantially vertically extending fin and the sliding surface in engagement therewith where the sliding surface is not entirely smooth, i.e., has an undulating or wavy surface.
These and other problems are solved or minimized by the overhanging barrier fin weatherstrip of this invention.